1. Field of the Invention
The present invention relates to an optical communication element, and more particularly to an optical power splitter of a planar lightwave circuit (PLC) type.
2. Description of the Related Art
In general, an optical power splitter is used for channeling input light into several different paths and has a wide application in an optical communication system, an optical access network, etc. The optical power splitter is classified into 1×2, 1×4, 1×8, . . . 1×N (where N is a natural number) types according to the number of its output terminals.
There are two representative methods used to manufacture an optical power splitter: a method of fusing an optical fiber in a melting-drawing manner and a PLC type method. Generally, the melting-drawing method is used in the systems having low channels, such as 1×2, 1×4, etc., whereas the PLC method is used in the systems with over 8 channels.
Although the PLC method considered a better choice over the melting-drawing method, it is not widely used due to its limitation in the number of channels and its high manufacturing cost. Even when the number of channels are reduced, the manufacturing cost will not be reduced. For example, the cost required for manufacturing an optical power splitter with four optical splitters of a 1×2 PLC type is twice or three times the cost of manufacturing an optical power splitter with one only optical splitter of a 1×8 PLC type. In addition, the manufacturing cost of the 1×2 PLC type per channel is twice or three times that of the 1×8 PLC type.
FIG. 1 illustrates the basic structure of the conventional optical power splitter with four 1×2 (i.e., 4(1×2)) optical splitters. As shown in FIG. 1, the conventional optical power splitter has a dicing line for cutting the splitter into individual elements. Thus, the conventional optical power splitter requires a space for accepting four divided modules which has an adverse effect in the in chip size. In addition, in the conventional optical power splitter, time for assembling the each optical splitter is mostly spent in housing the splitters, thus an efficient work time and material cost cannot be realized.